Network service providers are increasingly providing network services such as security, tunneling, virtual private networks, filtering, load-balancing, VoIP/Multimedia processing and various types of application proxies (HTTP, XML, WAP, etc.) to packet flows from customer devices. Service providers also provide content-specific services designed to improve the quality of a user's experience, for example, video streaming and caching. To provide these new services, service providers have often turned to specialized, dedicated physical or virtual appliances in some cases, routers or other network device have been modified to include additional hardware or software that applies various services to the incoming packets. For example, line cards installed in a service plane of a router may be configured to perform particular services, such as the services described above. In other example, service providers have deployed sophisticated service complex of specialized physical and/or virtual appliances to apply services to customer packet flows.